• Journal of Microbiology and Biotechnology
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• v.21 no.3
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• pp.243-251
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• 2011

The gene bolA was discovered in the 80's, but unraveling its function in the cell has proven to be a complex task. The BolA protein has pleiotropic effects over cell physiology, altering growth and morphology, inducing biofilm formation, and regulating the balance of several membrane proteins. Recently, BolA was shown to be a transcription factor by repressing the expression of the mreB gene. The present report shows that BolA is a transcriptional regulator of the dacA and dacC genes, thus regulating both DD-carboxypeptidases PBP5 and PBP6 and thereby demonstrating the versatility of BolA as a cellular regulator. In this work, we also demonstrate that reduction of cell growth and survival can be connected to the overexpression of the bolA gene in different E. coli backgrounds, particularly in the exponential growth phase. The most interesting finding is that overproduction of BolA affects bacterial growth differently depending on whether the cells were inoculated directly from a plate culture or from an overnight batch culture. This strengthens the idea that BolA can be engaged in the coordination of genes that adapt the cell physiology in order to enhance cell adaptation and survival under stress conditions.

• Kyungpook Mathematical Journal
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• v.28 no.1
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• pp.51-62
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• 1988

In this work we study properties of five identities of Bol-Moufang type (1). We establish a necessary and sufficient condition for a loop to be an RC-loop. A corollary to this is the condition for a Bol loop to be an RC-loop. Some proerties of a generalization of RC-loops are discussed. We also state the relationship between the supernucleus M(G) of a loop G and the nucleii of loops which do not have the inverse property. Finally, we give two tables of non-associative RC-loops of order 16, which are not Bol loops.

• Proceedings of the Zoological Society Korea Conference
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• 1997.10b
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• pp.277.2-277
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• 1997

No Abstract, See Full Text

• Journal of Microbiology and Biotechnology
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• v.22 no.4
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• pp.484-493
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• 2012

BolA protein homologs are widely distributed in nature. In this report, we have studied for the first time YrbA, the only BolA homolog present in Escherichia coli, which we have renamed ibaG. We have constructed single and multiple ibaG mutants, and overexpressed ibaG in wild-type strains, in order to characterize this gene. The ibaG phenotypes are different from the bolA-associated round morphologies or growth profiles. Interestingly, ibaG and bolA single-and double-deletion mutants grow faster and have higher viabilities in rich media, whereas the overexpressed strains are significantly growth impaired. However, the mutant strains have lower viabilities than the wild type in the late stationary phase, indicating that both bolA and ibaG are important for survival in difficult growth conditions. bolA, as a transcription factor, binds to some promoters, but ibaG does not interact with the same DNA regions. We have determined that ibaG is transcribed in an operon with the murA gene, involved in the synthesis of peptidoglycan precursors. ibaG was also seen to change its mRNA expression pattern in response to acidic stress. ibaG may thus represent a new gene involved in cell resistance against acid stress.

• Journal of the Microelectronics and Packaging Society
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• v.20 no.4
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• pp.53-58
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• 2013

An innovative packaging solution, Flip Chip with Copper (Cu) Column bond on lead (BOL) Enhanced Process (fcCuBE$^{(R)}$) delivers a cost effective, high performance packaging solution over typical bond on capture pad (BOC) technology. These advantages include improved routing efficiency on the substrate top layer thus allowing conversion functionality; furthermore, package cost is lowered by means of reduced substrate layer count and removal of solder on pad (SOP). On the other hand, as electronic packaging technology develops to meet the miniaturization trend from consumer demand, reliability testing will become an important issue in advanced technology area. In particular, electromigration (EM) of flip chip bumps is an increasing reliability concern in the manufacturing of integrated circuit (IC) components and electronic systems. This paper presents the results on EM characteristics on BOL and BOC structures under electrical current stressing in order to investigate the comparison between two different typed structures. EM data was collected for over 7000 hours under accelerated conditions (temperatures: $125^{\circ}C$, $135^{\circ}C$, and $150^{\circ}C$ and stress current: 300 mA, 400 mA, and 500 mA). All samples have been tested without any failures, however, we attempted to find morphologies induced by EM effects through cross-sectional analysis and investigated the interfacial reaction characteristics between BOL and BOC structures under current stressing. EM damage was observed at the solder joint of BOC structure but the BOL structure did not show any damage from the effects of EM. The EM data indicates that the fcCuBE$^{(R)}$ BOL Cu column bump provides a significantly better EM reliability.

• The Bulletin of The Korean Astronomical Society
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• v.40 no.1
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• pp.80.1-80.1
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• 2015

We present a study of outflows on 24 embedded young stellar objects selected from the source list of the Dust, Ice, and Gas in Time (DIGIT) Herschel key program. To study the relation between the CO outflows observed in low-J transitions and the properties of protostars more consistently with a homogeneous data set, we mapped the CO outflows of the selected targets in the J = 1-0 and J = 2-1 lines with two Korean telescopes (SRAO and TRAO). We compare CO outflow force ($F_{CO}$) with the bolometric luminosity, ($L_{bol}$) bolometric temperature, and the FIR molecular line luminosities of CO, $H_2O$, OH, and [O I] detected by the Herschel-PACS observations. We find that $F_{CO}$ of J = 1-0 is greater than that of 2-1 by a factor of ~ 2. The well known correlation between $F_{CO\;2-1}$ and $L_{bol}$ is not very evident in our sample as a whole, but they show a rather strong correlation when IRAM 04191+1522 is excluded. IRAM 04191+1522 has relatively high $F_{CO\;2-1}$ in spite of its low $L_{bol}$. This object is a well-known VeLLO, which is believed in the quiescent phase of the episodic mass accretion in the embedded stage. $L_{bol}$ traces a current accretion, but $F_{CO\;2-1}$ traces accretion happened long ago. Therefore, the low-$L_{bol}$ with the high-$F_{CO\;2-1}$ can be explained by the episodic accretion. $F_{CO\;2-1}$ shows little correlation with individual FIR line luminosities of CO, $H_2O$, OH, while [O I] and total FIR line luminosity seem to have correlations with $F_{CO\;2-1}$. This result is interpreted as the accretion energy deposits on species differently depending on shock properties, but the total FIR line luminosity sums the total accretion energy dispersed to different species.

• The Bulletin of The Korean Astronomical Society
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• v.37 no.1
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• pp.81.1-81.1
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• 2012

Herschel Key Program 중의 하나인 "Dust, Ice and Gas In Time (DIGIT)"의 관측 및 분석결과를 발표하고자 한다. 특히 DIGIT 천체들 중 Photodetector Array Camera and Spectrometer (PACS)로 관측된 별생성 초기 단계에 있는 embedded objects들의 FIR SED와 CO, $H_2O$, OH, [OI], [CII]의 FIR 천이선들의 공간분포와 생성기작을 분석한다. 뿐만 아니라, 원시성의 특성들($L_{bol}$과 $T_{bol}$)과 이들 각 분자/원자선에 의한 냉각률의 관계를 통계적으로 분석한 결과를 제시한다.

• Proceedings of the Korean Nuclear Society Conference
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• 1996.11b
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• pp.703-710
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• 1996

본 연구에서는 영광 3,4호기 원자로의 Core Support Barrel 거동을 중성자 잡음해석을 이용하여 분석하였다. 분석 방법은 원자로 노외계측기에서 취득한 교류 성분의 중성자 잡음 신호를 주파수분석하므로서 얻어진 PSD, Phase, Coherence 등을 이용하였다. 영광 3,4호기의 1 주기 동안의 신호를 분석결과, CSB의 Beam Mode 주파수는 영광 3호기의 경우 BOL, MOL, EOL에서 각각 7.75∼8.5Hz, 7.75Hz, 7.25∼7.75Hz로 나타났고, 영광 4호기 BOL에서 8.5∼8.75Hz 임이 도출되었다. 본연구 결과는 한국형 원전의 원자로 내부구조물의 진동 특성을 파악하고 운전중 CSB건전성 진단을 위한 기초 자료로 활용할 수 있다.

• Asia Pacific Journal of Corpus Research
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• v.1 no.1
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• pp.31-60
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• 2020

This paper investigates changes in relativization in Singapore English broadsheet newspapers from 1993 to 2016. One of the first diachronic studies in Singapore English (SgE), it also explores corresponding data from the diachronic Siena-Bologna (SiBol) news corpus. As SgE is in the endonormative stabilization phase in Schneider's (2007) Dynamic Model of postcolonial Englishes, divergence from British English (BrE) is to be expected. In this study, the dataset is a new Singapore English Newspaper (SEN) corpus compiled from local news articles in 1993, 2005 and 2016, and the corpus tool employed is Sketch Engine. The results reveal changes in relativization practices in SEN over the given period, many of which occur in a similar pattern as those identified in SiBol, albeit at varying rates of change. Most significant of these include a sharp decline in the which relativizer in restrictive relative clauses with non-animate antecedents, complemented by a rise in that. The change has been so rapid that although which relative clauses were more common than that clauses in 1993, that has subsequently overtaken which for both the corpora. One shift in SEN that is different from SiBol is the increase in frequency of non-restrictive relative clauses in SgE. The likely motivators for the changes in the two varieties are identified as colloquialization, densification and prescriptivism. The effect each of these factors could have had on the varieties are discussed, as well as the implications that the findings have on our understanding of the evolutionary status of SgE as a postcolonial variety.

• Bulletin of the Korean Mathematical Society
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• v.18 no.2
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• pp.65-68
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• 1982